Microphone always mutes when switching sides with partner

Hi all.

I've been supporting my 91 year old Dad in a nursing home. We go back and forth between our systems showing each other apps and files. Every time we switch sides it's necessary for us both to un-mute our microphones. We have to stop talking for about 10-15 seconds until the audio kicks in again (if he remembers to click the button!). Teamviewer is a great tool and I can live with this if I have to but I wonder if there is a setting somewhere to keep the microphone going when a switch happens. If I had to hazzard a guess, I imagine it's probably some sort of security feature built-in to the application. Thanks in advance for advice. Mark